Design and fabrication of the self-aligned opposed gate-source transistor

The authors report on the modeling, design, and successful realization of the self-aligned opposed gate-source transistor (OGST). An advanced distributed traveling-wave mathematical model of the OGST is used to determine the optimal gate width for 94-GHz operation. A novel fabrication process is described that utilizes a new lithography technique, resonant refractive index lithography, to self-align a 0.15- mu m source to a 0.3- mu m gate on opposite sides of a 0.2- mu m-thick GaAs active layer. The authors report on the DC operating characteristics of the self-aligned OGST and compare these results with theoretical models.<
>